Stitch adjuster for sewing machines



Sept. 8, 1936'.A H. H. wooDwARD ET AL.

STITCH ADJUSTER FOR SEWING MACHINES Filed Jan. 5, 1932 e yINVENTORS BY Wm TTORNEY Patented Sept. 8, 1936 UNITED `STATES yPATENT OFF I CE STITCH ADJUSTER FOR SEWING MACHINES New .York

Application January s, 193e, serial 10.584.358

11 Claims.

Our invention consists 'in improved :form of stop for the adjuster having a fixed notch.

In the accompanying Vdrawing we have shown one form of our invention, wherein Eiig. 1 is a perspective view of a sewing machine, provded'with our new adjuster;

Fig. 2 isa front view -of the `machine, partly in section, showing in detail the application of our device thereto;

Figs. 3 and 4 show our adjuster under diieren't conditions.

It is at present the standard practice to adjust for length of a sewing machine stitch by connecting `the outer -of `the regulating lever to different points on the -frame of the machine by means of a clamp operated 'by a thumb screw. This clamp, together with the vend of said regulating lever, is moved up or down, according to the desired length of stitch, and, at 'the proper '20 point, the clamp is fastened to the machine frame vby tightening the thumb vscrew down solidly against the side of the machine. In this old mode, a change of adjustment requires lthat the clamp be loosened by releasing the thumb screw,

and its new position ascertained by experiment before reciamp'ing it. That takesV time and ycareful attention.

It is also diiiicult to fix -the adjustment always at exactly the same point, in order to give the same length of stitch that was secured by `a previous adjustment. A manufacturer, making superior goods and particular about uniformity of stitch, finds this objectionable. It a'lso requires y care and takes time. which should not be lost. Moreover, the adjustment is in the control ofthe operative, who is tempted tomake the stitch 'too long, that is, fewer to the inch, whereby she 'can make more money. K

In Vsome cases the manufacturer has plugged 40 the adjuster at a certain point for a fixed number of stitches per inch. That is not desirable, because diierent machines cannot be plugged at the same point for-a given length of stitch. Also, a plugged machine, when vit becomes worn, will vcease to maintain the desired length of `stitch and for machines requiring frequent changes in the 'length of stitch, plugging is notl available.

The purpose of our invention is a device that makes changes of stitch-length more quick, vcertain and easy than heretofore and also accurate for two different lengths, for instance, one length for the running operation and another for the stitching down operation. The machine can then only operate at those two lengths of stitch.

5 This adjuster cannot be readily tampered with,

(Cl. 11H10.)

because it requires for 'its lmanipulation a special wrench. It is valso independent of wear in the feeding mechanism and requires much less -su' pervision of the opera-tives. A

Thus, 'a 'cuff 'is usually constructed of three plies i5 of material, -a facing, an interiining and a backing. 'The interlining, and sometimes, also, the backing, are rst applied to the Vend of 'the sleeve, and this may be done by a long stitch, because this seam is hidden from viewfin the nished gar' 1'0 men-t. jThis is called running. But when the edge of the facingis turned over `and the three plies, together with the sleeve, are to -be lstitched together, the resulting seam vwill be visible in the linished article, so it must be made with a lb short A'sti-tch. v'lhat is ytrailed stitching down. Bot-h running and stitching down are performed by one operator who also makes the adjustment ychanges for the two different-lengths Vof stitch. zo

Referring to the drawing, Fig. 2 shows one well known 'form of stitch adjustment mechanism. In this Fig. V2 -F represents the main horizontal shaft of Ythe machine; E is ra cam on said shaft which oscillates a `fork Gon rod H and said rod 2o H is connected vby a bell crank J to the left hand end of the -feed member K. -These elements serve to give a forward and backward movement to the feed member K. The right-hand end of feed member K contains a slot in which rides a rol-ler so on the end of lever L and lever L, by means of lever M, is worked up and down through the agency of rod I leading up to a cam on the aforesaid main shaft F.

O is the stitch vadjuster or regulator. It is 'Se a 'lever which is oscillated around its iixed center P to provide for changes in the length of fabric feed `per stitch. The left-hand -end `of'sai-d lever O is connected by link Q to the fork G aforesaid. 'Lever L aforesaid -ac'ts to `raise the Lteed '40 member up fand down, while lever J works it forward and back as `just described.

Thereby the feeding teeth on the `top surface of feeding member K are rlrst .raised slightly to engage the fabric then 'moved leftward the irdis- 45 tance of a stitch, then drawn downward from the fabric, and returned .back clear of the fabric to its starting point at its lower level. The .length 'of the stitch thus made may be increased or l, diminished by working the regulator lever O, and 50 thereby changing the angle of 'the link Q. The mechanism above described constitutes no part of our present invention, being `old and standard and here shown merely for illustration. y Our invention herein relates to the control of the said regulator lever O to give its right-hand end an exactly determined position with respect to the frame or casing R of the machine. For this purpose we enter a screw S into the end of lever O and the outer end of said screw S is extended through a slot in the casing R and jointed to the top I of a vertical vrod B outside of the casing.l A spring W surrounds the lower end of this rod B and reacts against a bracket V fixed on the casing R to press the rod B downward. This spring is suiiciently strong to prevent oscillation of the feed. There is a toe vC projecting out from the rod B near the lower end thereof, and secured to said rod by nuts T. The said spring W bears at its lower end against the top of said nuts T and thereby tends to force the rod B constantly downward and to also force down with rod B the outer end ofthe aforesaid regulator lever O which is jointed to B.

If the said toe C on the lower end of 'rod B does not encounter any stop the spring W will force it, and also the rod B to which it is attached, clear down and so pull the outer righthand end of the regulator lever O down to its limit, that is, down till it strikes the bottom edge of the slot in casing Rl through which the outer end of lever O protrudes or till the lower end of rod B strikes the iioor of the frame R at e as shown in Fig. 4. Another stop for rod B is provided by a pivoted plate D, pressed up by a spring U. This plate D has a notch in its upper lefthand corner, and a projection or handle a. The spring U normally tends to move the plate D to the position shown in Figure 3, but by means of the handle a said plate may be tilted against the tension of said spring, to the position illustrated in Figure 4. While said plate is tilted to the latter position, the toe C is permitted to pass by the notch b till the lower end of rod B strikes the floor of the frame R as Shown in Fig. 4.

Moreover, bymeans of a special wrench, the nuts T T can be set up or down to shift the position of the toe C with relation to rod B in order to compensate for wear. Such compensation is only required at rare intervals and are made by the inspector while the changes which the operative can make are easy, simple and accurate. They are of a different class from those requiring the attention of the inspector. By screwlng the nut Y down on the rod B so that the member V would act as a stop, it is possible to obtain a considerable intermediate variation in the number of stitches per inch within the range determined by previous adjustments of the nuts T relative to the stop V. Upon adjustment of the nuts T, the distance of the lower end of rod B from the base R may be varied when the member C engages stop b.

By the above-described device the adjustment which the operative needs to make may be set, instantly, positively and accurately to any one of two or more positions, without the need of screwing down a clamp to get a frictional grip on which the adjustment depends, as in the previous art.

What we claim as new and desire to secure by Letters Patent is:-

1. A stitch-length adjuster for sewing ma-l chines comprising a movably supported stitch regulator, a rod connected at one end with an end of said stitch regulator, a fixed abutment positioned to engage the other end of said rod, and controllable abutment means positioned to engage and maintain said other end of the rod at a location spaced from said fixed abutment.

2. A stitch-length adjuster for sewing machines comprising a movably supported stitch regulator, a rod connected at one end with an end of said stitch regulator, a xed abutment positioned to engage the other end of said rod, and a movable member having an'abutment portion positioned to maintain said other end of the rod at a location spaced from said fixed abutment.

3.-A stitch-length adjuster for sewing machines comprising a movably supported stitch f regulator, a rod connected at one end to and depending from an end of the stitch regulator, a fixed abutment positioned to engage the lower end of said rod, a controllable abutment positioned to maintain the lower end of the rod at a location spaced from the fixed abutment, and a spring acting normally to press said rod downwardly s o as to prevent feed oscillation acting upon said adjuster member.

4. A stitch-length adjuster for sewing machines comprising a movably supported stitch regulator, a rod connected to and depending from said regulator, a fixed abutment positioned to engage the lower end ofl said rod, a spring acting normally to move said rod toward said fixed abutment, and a tiltable member supportedadjacent to said xed abutment and having a second abutment so positioned as to maintain the lower end of said rod at a location spaced from said fixed abutment.

5. A stitch-length adjuster for sewing machines comprising a pivoted stitch regulator, a spring pressed rod connected at one end with said regulator and depending therefrom, a fixed abutment positioned to engage the lower end of said rod, and a spring pressed controllable abutment member having an abutment portion positioned to engage and maintain the lower end of the `rod at a location spaced from said xed abutment.

6. A stitch-length adjuster for sewing machines comprising a movably supported stitch regulator, a spring pressed rod connected at one end to said regulator and depending therefrom, a fixed abutment portion positioned to engage the lower end of said rod, an abutment toe carried by said rod and spaced from the lower end thereof, and other controllable abutment means complemental to said toe.

7. A stitch-length adjuster for sewing machines comprising a pivoted stitch regulator, a spring pressed rod connected at one end with said regulator and depending therefrom, a fixed abutment positioned to engage the lower end of said rod, an abutment toe movably mounted on said rod, means for adjustably maintaining said toe in spaced relation with respect to the lower end of said rod, and other controllable abutment means complemental to said toe.

8. A stitch-length adjuster for sewing machines comprising a pivoted stitch regulator, a rod pivotally connected at one end to an end of the regulator and depending therefrom, and means for maintaining said regulator in adjusted positions, said means being constructed and arranged to engage the lower portion of said rod.

9. A stitch-length adjuster for sewing machines comprising a pivoted regulator, a rod pivoted at one end to said regulator and depending therefrom, a xed abutment member positioned to engage the lower end of said rod, an abutment toe mounted on the lower portion of said rod, a

fixed abutment engaging said rod, a spring interposed between said toe and the last-mentioned fixed abutment, and other controllable abutment means complemental to said toe.

10. A stitch-length adjuster for sewing machines comprising a pivoted regulator, a rod pivoted at one end to said regulator and depending therefrom, a fixed abutment member positioned to engage the lower end of said rod, an abutment toe mounted on the lower portion of said rod, a xed abutment engaging said rod, a spring interposed between said toe and the last mentioned fixed abutment, a nger piece carried by said rod, and a pivoted abutment member having abutment means complemental to said toe.

11. A stitch-length adjuster for sewing machines comprising a pivotally supported stitch regulator, a rod connected at one end with an end of said stitch regulator and depending therefrom, a spring normally acting to force said rod downwardly, a xed abutment positioned to engage the lower end of said rod, an abutment toe movably engaging said rod, means for adjusting said abutment toe toward and from the lower end of said rod, a pivoted member mounted adjacent said xed abutment and provided with an abutment shoulder complemental to said toe, and a spring normally acting to move said pivoted member to a predetermined position.

HERMON H. WOODWARD. ALPHA H. WRIGHT. 

